Alternative mRNA splicing, also known as alternative splicing or differential splicing, refers to a post-transcriptional process in molecular biology that occurs in eukaryotic cells. It is a mechanism by which multiple mature mRNA molecules can be generated from a single, primary RNA transcript (pre-mRNA). Alternative splicing allows for the production of different protein isoforms with distinct functions from the same gene.
During alternative mRNA splicing, specific exons (coding sequences) within the pre-mRNA can be retained or excluded, resulting in the formation of different splice variants. Exons that are included in the mature mRNA sequence are known as exonic sequences, while intronic sequences are spliced out and typically degraded. The choice of exons can vary across different cell types, development stages, or in response to various external stimuli.
This orchestrated process is regulated by proteins called splicing factors, which bind to specific sequences on the pre-mRNA, guiding the formation of different splice variants. Alternative mRNA splicing significantly increases the diversity of the proteome by generating different mRNA isoforms that can produce distinct protein products with specialized functions, tissue-specific expression patterns, or differential regulatory properties.
This molecular mechanism plays a crucial role in biological processes such as embryonic development, tissue differentiation, and response to environmental changes. Dysregulation of alternative splicing has been implicated in various human diseases, including neurological disorders, cancers, and genetic syndromes. Consequently, studying alternative mRNA splicing has become an important area of research to gain insights into the complexity of gene expression and its impact on cellular functions and diseases.
